X Is What Percent of Y?

Expressing one number as a percentage of another turns raw quantities into shares you can compare: test marks, market share, progress toward a goal, or what portion of a budget is spent. It's a single division dressed up as a percentage.

What is % of ?
is what percent of ?
Percentage change from to ?

The formula

Percent = (X ÷ Y) × 100

How to calculate it

  1. Divide the part (X) by the whole (Y).
  2. Multiply the result by 100.
  3. Add the % sign — that's X as a share of Y.

Worked example

30 is what percent of 150? 30 ÷ 150 × 100 = 20%.

Quick reference table

PartWholePercent
3015020%
456075%
2520012.5%
124825%
9930033%
150120125%

Related percentage calculators

Or use the general percentage calculator for all three percentage questions in one place.

Frequently asked questions

How do I work out what percent X is of Y?

Divide X by Y and multiply by 100. For example, 45 out of 60 is 45 ÷ 60 × 100 = 75%.

Can the answer be more than 100%?

Yes — when the part exceeds the whole. 150 is 125% of 120. That's common with targets: hitting 150 sales against a 120 goal is 125% of target.

Which number goes on top?

The number being measured (the part) is divided by the number it's compared against (the whole). '30 is what % of 150' means 30 ÷ 150, not 150 ÷ 30.